Customize for my website

Hello! I am needing assistance customizing this plug-in for my website. I am creating a site for people who work as crew members on cruise ships and marine ships to search up businesses by ports of call and country. Businesses pay for their listings and offer a discount for their business to be promoted to crew. I know nothing about coding. I know the exact functionality I require and can give more in depth idea if you reply.

Any quote will be checked via other web developers to make sure the price is fair. I know there isn’t too much work required for this. I just don’t know how to code.